Hyperlipidemia is a risk factor for lymphatic metastasis in superficial esophageal carcinoma

Although increased dietary fat or cholesterol has been reported to be a risk factor for the development of certain cancers, the effect of the serum lipid level on tumor metastasis has not been well documented. Fasting serum levels of total cholesterol (TC) and triglycerides (TG) were examined in 54 patients with superficial esophageal cancer (SEC) invading lamia musucularis or submucosal layer who underwent esophagectomy with classical lymphadenectomy. The association between lymph node metastasis and the preoperative serum lipid levels as well as the pathological findings was retrospectively analyzed. The levels of TC and TG were significantly higher in 18 node-positive than in 36 node-negative patients (TC: 205.4±38.9 vs. 174.5±26.8 mg/dl, P<0.01; TG: 152.0±68.5 vs. 88.7±28.6 mg/dl, P<0.001). Patients with hypercholesterolemia (TC≧220 mg/dl) and hypertriglyceridemia (TG≧150 mg/dl) showed extremely high rates of nodal metastasis (80 and 91%, respectively), that were significantly higher than those of patients with normal lipid levels (P<0.01 and P<0.001). When hyperlipidemia was defined as the presence of either hypertriglyceridemia or hypercholesterolemia, hyperlipidemia was an independent risk factor for nodal metastasis in SEC. Elevated serum lipid levels might bring favorable circumstances for the development of lymph node metastasis in the early stage of EC. Hyperlipidemia might prompt us to perform more studies to investigate possible metastasis.